The present application claims priority to Japanese Application No. P10-061689 filed Mar. 12, 1998 which application is incorporated herein by reference to the extent permitted by law.
1. Field of the Invention
This invention relates to a rotary drum in which a magneto-resistive effect magnetic head is used as a reproducing magnetic head, and to a helical scan magnetic recording/reproducing apparatus carrying the rotary drum.
2. Description of the Related Art
In a magnetic recording/reproducing apparatus, such as a video tape recorder, audio tape recorder or a data storage system for a computer, employing a magnetic tape as a recording medium, there is adopted a helical scan system for improving the recording density to increase the recording capacity.
In this magnetic recording/reproducing apparatus, a higher recording density and a larger recording capacity are desired. For realizing this higher recording density and a larger recording capacity, it has been proposed to use a magneto-resistive effect magnetic head (MR head) as a playback magnetic head in the helical scan magnetic recording/reproducing apparatus.
The MR head uses a magneto-resistive effect element (MR element) as a magnetically sensitive element for detecting the magnetic field from the recording medium, and is put to practical use as a playback magnetic head of the hard disc drive. In general, the MR head is higher in sensitivity than the inductive magnetic head and is able to develop a large playback output. Thus, by using the MR head as the playback magnetic head, it is possible to realize a still higher recording density and a still larger recording capacity.
Meanwhile, in a hard disc drive, the MR head is loaded on the floating slider, so that data is reproduced under a condition in which the MR head is floated over the magnetic disc. On the other hand, if the MR head is used for the helical scan system, data is reproduced from the magnetic disc as the MR head is kept in sliding contact with the magnetic tape.
However, if the MR head is kept in sliding contact with the magnetic tape, there is presented a problem that, even if the playback output of the MR head is larger, the MR head is worn out due to its sliding contact with the magnetic tape. If the MR head is worn out, the playback output level is fluctuated to increase the noise and so-called dropout. For this reason, the helical scan magnetic recording/reproducing apparatus employing the MR head as the playback magnetic head has as yet not been put to practical use.
It is therefore an object of the present invention to provide a rotary drum device employing the MR head as the playback magnetic head, and a magnetic recording/reproducing apparatus of the helical scan system.
In one aspect, the present invention provides a rotary drum device including a cylindrically-shaped rotary drum, an inductive magnetic head loaded on the rotary drum so that a portion thereof is protruded from the outer periphery of the rotary drum, and a magneto-resistive effect magnetic head loaded on the rotary drum so that a portion thereof is protruded from the outer periphery of the rotary drum. An amount of protrusion from the outer periphery of the rotary drum of the magneto-resistive effect magnetic head is selected to be smaller than an amount of protrusion from the outer periphery of the rotary drum of the inductive magnetic head.
In the rotary drum device according to the present invention, in which the amount of protrusion of the magneto-resistive effect magnetic head is selected to be smaller than that of the inductive magnetic head, the contact pressure between the magneto-resistive effect magnetic head and the magnetic tape is smaller than that between the inductive magnetic head and the magnetic tape.
In another aspect, the present invention provides a rotary drum device including a cylindrically-shaped rotary drum, an inductive magnetic head loaded on the rotary drum and having a cylindrical sliding surface for the magnetic tape and a magneto-resistive effect magnetic head loaded on the rotary drum and having a cylindrical sliding surface for the magnetic tape. The radius of curvature of the sliding surface for the magnetic tape of the magneto-resistive effect magnetic head is selected to be larger than that of the sliding surface for the magnetic tape of the inductive magnetic head.
In this rotary drum device according to the present invention, in which the radius of curvature of the sliding surface of the magneto-resistive effect magnetic head is selected to be larger than that of the sliding surface of the inductive magnetic head, the contact pressure between the magneto-resistive effect magnetic head and the magnetic tape is smaller than that between the inductive magnetic head and the magnetic tape.
In still another aspect of the present invention, the present invention provides a magnetic recording/reproducing apparatus which is a helical scan magnetic recording/reproducing apparatus including a cylindrically-shaped rotary drum, an inductive magnetic head loaded on the rotary drum so that a portion thereof is protruded from the outer periphery of the rotary drum, and a magneto-resistive effect magnetic head loaded on the rotary drum so that a portion thereof is protruded from the outer periphery of the rotary drum. An amount of protrusion from the outer periphery of the rotary drum of the magneto-resistive effect magnetic head is selected to be smaller than an amount of protrusion from the outer periphery of the rotary drum of the inductive magnetic head.
In this magnetic recording/reproducing apparatus according to the present invention, in which the amount of protrusion of the magneto-resistive effect magnetic head is selected to be smaller than that of the inductive magnetic head, the contact pressure between the magneto-resistive effect magnetic head and the magnetic tape is smaller than that between the inductive magnetic head and the magnetic tape.
In yet another aspect, the present invention provides a helical scan magnetic recording/reproducing apparatus including a cylindrically-shaped rotary drum, an inductive magnetic head loaded on the rotary drum and having a cylindrical sliding surface for the magnetic tape and a magneto-resistive effect magnetic head loaded on the rotary drum and having a cylindrical sliding surface for the magnetic tape. The radius of curvature of the sliding surface for the magnetic tape of the magneto-resistive effect magnetic head is selected to be larger than that of the sliding surface for the magnetic tape of the inductive magnetic head.
In this magnetic recording/reproducing apparatus according to the present invention, in which the radius of curvature of the sliding surface of the magneto-resistive effect magnetic head is selected to be larger than that of the sliding surface of the inductive magnetic head, the contact pressure between the magneto-resistive effect magnetic head and the magnetic tape is smaller than that between the inductive magnetic head and the magnetic tape.